49 research outputs found

    Spartan Daily, March 18, 1971

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    Volume 58, Issue 88https://scholarworks.sjsu.edu/spartandaily/5496/thumbnail.jp

    ONLY PROBLEMS, NOT SOLUTIONS!

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    The development of mathematics continues in a rapid rhythm, some unsolved problems are elucidated and simultaneously new open problems to be solved appear

    Spartan Daily, March 18, 1971

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    Volume 58, Issue 88https://scholarworks.sjsu.edu/spartandaily/5496/thumbnail.jp

    Voter verifiability in homomorphic election schemes

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2005.Includes bibliographical references (leaves 61-64).Voters are now demanding the ability to verify that their votes are cast and counted as intended. Most existing cryptographic election protocols do not treat the voter as a computationally-limited entity separate from the voting booth, and therefore do not ensure that the voting booth records the correct vote. David Chaum and Andrew Neff have proposed mixnet schemes that do provide this assurance, but little research has been done that combines voter verification with homomorphic encryption. This thesis proposes adding voter verification to an existing multi-candidate election scheme (Baudron et al.) that uses Paillier encryption. A "cut and choose" protocol provides a probabilistic guarantee of correctness. The scheme is straightforward, and could easily be extended to multi-authority elections. The feasibility of the proposed scheme is demonstrated via a simple implementation.by Joy Marie Forsythe.M.Eng

    The transmission of music into the human uterus and the response to music of the human fetus and neonate

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    The aim of this study was to investigate whether music influences human life before birth. In order to determine the existence and character of music in the uterine acoustic environment, a study was conducted involving the insertion of a hydrophone through the cervix, next to the fetal head. The investigation was conducted on eight women in early labour. The average residual uterine sound of the eight subjects was measured at 65 dBA (A-weighted) re 20 µ.Pa in a 1 O KHz band, RMS averaged over 32-second records. Above this emerged the maternal voice, an external female voice and a male voice presented at approximately 65 dB (linear weighted). Pure tones between 50 Hz and 1 O KHz and orchestral music, all presented at 80 dB (linear weighted), were also shown to emerge above the residual uterine sound. Attenuation of external sound was observed to vary as a function of frequency, with less attenuation of lower frequencies. It was determined that the music was transmitted into the uterus without sufficient distortion to significantly alter the recognisable characteristics of the music. The fetal heart rate (FHA) response to a music stimulus (MS) and a vibroacoustic stimulus (VS) was measured in 40 subjects. Gestational age of the fetuses ranged from 32 to 42 weeks. The study included a control period with no acoustic stimulation; a period with the presentation of 5 music stimuli; and a period with the presentation of 5 vibroacoustic stimuli. A change in the FHA of 15 beats per minute or greater, lasting 15 seconds and occurring within 15 seconds of at least 2 of the 5 stimuli (or a tachycardia of greater than 15 beats per minute above the resting baseline, sustained for one minute or longer) was considered to be a positive response. The MS elicited a positive response in 35 of the fetuses (the 5 non-responses occurring in a period of low FHA variability) and all 40 fetuses responded to the VS (regardless of arousal state). In the third study, mothers attending childbirth education classes volunteered to listen to a prescribed music excerpt twice daily from the 34th week of pregnancy. Ten neonates (all clinically normal) were tested betw~en the 2nd and 5th day after birth. Investigators observed the effect of two music sti:Tiuli, the prescribed stimulus and a non-prescribed stimulus, on neonatal sucking of a non-nutritive nipple. A five-minute control period with no stimulation was compared with a ten-minute period during which two music stimuli were presented. By random allocation, either the prescribed music stimulus (PM) or the nonprescribed music (NM) was presented contingent upon sucking pressure. If a sucking burst was initiated, the PM stimulus was activated. On cessation of sucking, the NM stimulus was activated. Randomly, the procedure would be reversed for some of the subjects, where initiation of sucking activated the NM stimulus and cessation of sucking activated the PM stimulus. It was determined that the inter-burst intervals during the music period were significantly extended when coinciding with the PM stimulus and significantly shortened when coinciding with the NM stimulus.The studies indicated that music is transmitted into the uterus with insufficient distortion to alter the character of the music; that the normal fetus responds to a music stimulus from at least the 32nd week of gestation; and that the neonate alters the normal sucking pattern to activate longer periods of a music stimulus which has been repeatedly presented during the intrauterine stage and shorter periods of a novel music stimulus

    A Distributed Security Architecture for Large Scale Systems

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    This thesis describes the research leading from the conception, through development, to the practical implementation of a comprehensive security architecture for use within, and as a value-added enhancement to, the ISO Open Systems Interconnection (OSI) model. The Comprehensive Security System (CSS) is arranged basically as an Application Layer service but can allow any of the ISO recommended security facilities to be provided at any layer of the model. It is suitable as an 'add-on' service to existing arrangements or can be fully integrated into new applications. For large scale, distributed processing operations, a network of security management centres (SMCs) is suggested, that can help to ensure that system misuse is minimised, and that flexible operation is provided in an efficient manner. The background to the OSI standards are covered in detail, followed by an introduction to security in open systems. A survey of existing techniques in formal analysis and verification is then presented. The architecture of the CSS is described in terms of a conceptual model using agents and protocols, followed by an extension of the CSS concept to a large scale network controlled by SMCs. A new approach to formal security analysis is described which is based on two main methodologies. Firstly, every function within the system is built from layers of provably secure sequences of finite state machines, using a recursive function to monitor and constrain the system to the desired state at all times. Secondly, the correctness of the protocols generated by the sequences to exchange security information and control data between agents in a distributed environment, is analysed in terms of a modified temporal Hoare logic. This is based on ideas concerning the validity of beliefs about the global state of a system as a result of actions performed by entities within the system, including the notion of timeliness. The two fundamental problems in number theory upon which the assumptions about the security of the finite state machine model rest are described, together with a comprehensive survey of the very latest progress in this area. Having assumed that the two problems will remain computationally intractable in the foreseeable future, the method is then applied to the formal analysis of some of the components of the Comprehensive Security System. A practical implementation of the CSS has been achieved as a demonstration system for a network of IBM Personal Computers connected via an Ethernet LAN, which fully meets the aims and objectives set out in Chapter 1. This implementation is described, and finally some comments are made on the possible future of research into security aspects of distributed systems.IBM (United Kingdom) Laboratories Hursley Park, Winchester, U

    Laminar Flow Aircraft Certification

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    Various topics telative to laminar flow aircraft certification are discussed. Boundary layer stability, flaps for laminar flow airfoils, computational wing design studies, manufacturing requirements, windtunnel tests, and flow visualization are among the topics covered

    Secure multi party computations for electronic voting

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    Στην παρούσα εργασία, μελετούμε το πρόβλημα της ηλεκτρονικής ψηφοφορίας. Θεωρούμε ότι είναι έκφανση μιας γενικής διαδικασίας αποφάσεων που μπορεί να υλοποιηθεί μέσω υπολογισμών πολλαπλών οντοτήτων, οι οποίοι πρέπει να ικανοποιούν πολλές και αντικρουόμενες απαιτήσεις ασφαλείας. Έτσι μελετούμε σχετικές προσεγγίσεις οι οποίες βασιζονται σε κρυπτογραφικές τεχνικές, όπως τα ομομορφικά κρυπτοσυστήματα, τα δίκτυα μίξης και οι τυφλές υπογραφές. Αναλύουμε πώς προσφέρουν ακεραιότητα και ιδιωτικότητα (μυστικότητα) στην διαδικασία και την σχέση τους με την αποδοτικότητα. Εξετάζουμε τα είδη λειτουργιών κοινωνικής επιλογής που μπορούν να υποστηρίξουν και παρέχουμε δύο υλοποιήσεις. Επιπλέον ασχολούμαστε με την αντιμετώπιση ισχυρότερων αντιπάλων μη παρέχοντας αποδείξεις ψήφου ή προσφέροντας δυνατότητες αντίστασης στον εξαναγκασμό. Με βάση την τελευταία έννοια προτείνουμε μια τροποποίηση σε ένα ευρέως χρησιμοποιούμενο πρωτόκολλο. Τέλος μελετούμε δύο γνωστές υλοποιήσεις συστημάτων ηλεκτρονικής ψηφοφοριας το Helios και το Pret a Voter .In this thesis, we study the problem of electronic voting as a general decision making process that can be implemented using multi party computations, fulfilling strict and often conflicting security requirements. To this end, we review relevant cryptographic techniques and their combinations to form voting protocols. More specifically, we analyze schemes based on homomorphic cryptosystems, mixnets with proofs of shuffles and blind signatures. We analyze how they achieve integrity and privacy in the voting process, while keeping efficiency. We examine the types of social choice functions that can be supported by each protocol. We provide two proof of concept implementations. Moreover, we review ways to thwart stronger adversaries by adding receipt freeness and coercion resistance to voting systems. We build on the latter concept to propose a modification to a well known protocol. Finally, we study two actual e-Voting implementations namely Helios and Pret a Voter
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